Plug-in mount for a circuit unit



May 22, 1956 F. w. PARRISH 2,747,167

PLUG-IN MOUNT FOR A CIRCUIT UNIT Filed Jan. 4, 1954 /:/G./ F/6.Z F76. 3

IN V EN TOR. FRANK W FARR/Sh United States Patent 2,747,167 PLUG-IN MOUNT FOR A CIRCUIT UNIT Frank W. Parrish, Bellflower, Calif., assignor to International Rectifier Corporation, El Segundo, Caliti, a

corporation of California Application January 4, 1954, Serial No.. 402,019

' 1 Claim. Cl. 339-176 This invention pertains to electrical plug-in mounts, and has for an object the provision of a mount which simplifies the installation and replacement of circuit units. An additional object is to provide a plug-in mount capable of connection with circuit units of various sizes.

A feature of my invention resides in a mount having an insulating base provided with a resilient conductive female receptacle and a resilient conductive prong spaced apart from each other. A circuit unit may be plugged to the mount by inserting a male connection of the unit into the receptacle of the mount, and inserting the prong 0f the mount into a cavity of the circuit unit.

The novel mount is particularly applicable for use with dry plate rectifiers, such as selenium rectifiers, although it is useful with other types of circuit units as well.

These foregoing and other features of my invention will be fully understood from the following detailed description and the accompanying drawings, of which:

Fig. 1 is a plan view of a mount according to the invention;

Fig. 2 is a cross-sectional view taken at line 22 of Fig. 1;

Fig. 3 is a cross-section of an alternate form of the invention;

Fig. 4 is an elevation of a rectifier unit satisfactory for use with the mount of this invention; and

Fig. 5 is a cross-sectional view taken at line 5-5 of Fig. 4.

Referring to the drawings, Fig. 1 shows a mount according to the invention having an insulating strip for a base which may be of molded rubber, Bakelite, or some other insulating material. The strip is pierced by holes 11 for attaching the strip to a chassis. The strip also has slots 12 and 13, and a recessed seat 14 with an overhanging shoulder 14a. Another slot 15 pierces the strip from the inside of the seat.

A conductive male prong 16 of the common split banana type comprises four approximately quadrantal springing leaves 17, of spring metal or the like, which when assembled as shown with slits 18 between them, make up a prong of generally circular cross-section which can flex and expand or contract in a lateral direction with respect to the prongs longitudinal axis. A conductive cap 19, ordinarily of metal, clamps the leaves together and fits in the recessed seat under the shoulder 140. A conductive strip 19a is affixed to the cap, and passes through slot 15 so as to project from the strip. Leads and the like (not shown) may be soldered to this strip 19a so as to incorporate the male prong into an electrical circuit.

A spring clip 20 forms a female receptacle, and comprises a generally flat strip of metal, one end of which is inserted in slot 12 and projects therefrom to form a projection 21 for attaching leads to incorporate this receptacle into a circuit. At the other end of the strip there is a resilient bend or receptacle 22 which fits in slot 13.

The bend has two arms 23, which may be sprung apart to form the receptacle. These arms are on opposite sides. of the longitudinal axis of the receptacle, which longitudinal axis extends substantially perpendicularly from the base, and parallel to the longitudinal axis of the prong. The male prong and female receptacle face the same side of the strip. This entire mount may convenwhich is inserted into two slots 26, 27 with the receptacle in one slot, and the other end projecting from the rear of the other slot. Leads may be soldered to this projection. The spring clip is bound to the strip by a rivet 28. The male prong 29 is a hairpin type, which comprises a bent wire having two opposite elements 30, 31 with a space therebetween so that they may be compressed toward each other. This prong is fastened to the strip by a hollow rivet 32 which is made of conductive material. A conductive lug 33 is bound under the rivet on the side of the base away from the prong and projects to form a terminal to which leads may be soldered.

Figs. 4 and 5 show a dry plate rectifier which is well suited for use with the plug-in mounts of this invention. This is illustrative of an electrical circuit unit of which one terminal is a tubular cavity terminal 52 and the other terminal of which is a protruding lug terminal 48. While a rectifier is shown for purposes of illustration, the mount may also be used to plug in capacitance, resistance, inductance, or other circuit units in the same manner. This rectifier 40 comprises a number of dry rectifier elements 41 which are constructed in a well known manner. Each rectifier element has a square conductive base plate 42 which may be of iron or aluminum and having a coating 43 of metallic selenium on one surface for the active electrode. A coating 44 of another metal is sprayed onto the selenium for the counter-electrode. Such coatings are well known in the art, and need not be further described here. The relative dimensions of the selenium layer and metal layer 44 relative to the base plate are shown disproportionately thick in the drawings for purposes of illustration.

According to a well-known rectifier assembly arrangement, each base plate has a hole 45 at the center. A conductive spacer or washer 46 is placed between each adjacent plate, and the interleaved rectifier elements and spacers are placed onto a hollow tube 47 made of an insulating material such as Bakelite or fiber. The rectifier elements are all faced in the same manner so that they will act in series.

A bent strip to form lug terminal 48 having a hole for the tube 47 is placed over the lefthand end of the tube as shown in Fig. 5 and forms a male terminal for the rectifier. Then an insulating washer 49, preferably of fiber is placed over the tube 47 to the left of the portion of the strip forming the terminal lug which surrounds the tube. Two conductive washers 50, 500 are placed over the righthand end of the tube. Finally, a headed eyelet .51 is passed through the insulating tube with its formed head 51a to the left and bearing on the fiber washer. Its other end at 51b is crimped around the righthand end of the tube 47 so as to contact the conductive washers 50, 50a. The eyelet has a longitudinal central hole which forms the cavity for the cavity terminal 52 of the rectifier. The strip forming the terminal lug 48 is Patented May 22,. 1956 3 insulated from the eyelet by insulating washer 49 and tube-'47.

The number of rectifier elements used in a given rectifier is determined by its. intended use. The rectifier is shown 'inFig'. Stoillhstratethe stacking arrangements of the elements it being understood that the spacing between" the lug terminal 48 and washer 50' will be entirely filledwith a stack of rectifier elements 41 and spacers 46.

In use, an assembled mount such as is shown in Fig. 2, is" fixed as desired, for example. in a radio or television chassis, and the projecting leads'19a and 21 are soldered to leads so as to form a permanent part of an electrical circuit (not shown). Then the electrical circuit unit to be connected, such as a rectifier like that of Figs. 4 and rectifier is thereby positioned and held in place so that it cannot rotate. The sides of the metal prong make electrical contact with the eyelet, and the terminal lug makes electrical contact with the spring clip. The leaves of the male prong are initially spread apart so that insertion of the. prong into the tube squeezes them back together. This spring force makes a firm contact between the prong and wall.

By means of this mount, rectifiers or other circuit units may be installed and replaced in a circuit as simply as a vacuum tube in a socket. There are no joints to solder, or other clamping devices to be used. Only a plugging action is required.

This. mount is a universal type which can accommodate a wide range of unit sizes of all kinds including halfwave, radio and television rectifiers, or other circuit elements. Various sizes of circuit units may be mounted on an eyelet of agiven size for use with this mount, or, if preferred, the leaves of the male prong may simply be spread apart to make connection inside eyelets of differ- 4 ent diameters. When installed, these elements are automatically" positioned; and-'arerigidly supported by the mount.

This invention is not to be limited to the embodiments described in the description and illustrated in the drawings, which are given by way of illustration and not of limitation but only in accordance with the scope of the appended claim.

I claim:

A plug-in mount adapted to make connection with a circuit unit which unit is provided with a lug terminal and a cavity terminal, said mount comprising: a flat insulating base having twosides, said base having a pair of slots therethrough, and a recessed seat therein, a resilient receptacle comprising a fiat strip bent into a pair of spring arms for receiving said lug terminal, said spring arms being disposed in one of said slots and facing outward from one side of said base, said strip having a portion passing through the second of said slotsto the other side of the base, a conductive prong having a longitudinal axis, which prong is seated in said recessed seat, facing from the same side of the base as the receptacle, and comprising flexible elements for expanding laterally with respect to said longitudinal axis so as to be compressible when inserted into the said cavity terminal, and a conductive member attached to said prong and passing through the insulating base.

References Cited in the file of this patent UNITED STATES PATENTS 995,674 Hertzberg et al. June 20, 1911 1,671,540 Monteil Mar. 29, 1928 1,751,842 Propp Mar. 25, 1930 2,145,897 Sherman Feb. 7, 1939 2,455,324 Wagstaff" Nov. 30, 1948 2,517,677 Kjell-Berger et al. Aug. 8, 1950' 2,563,713 Frei et al. Aug. 7, 1951 

